Impulse generator



Jan. 30, 1940. L. E. NORTON 188,611

IMPULSE GENERATOR Filed June 18, 1938 Ffa. i.

Snoentor Lowell', E. Noron il) Continuously indicating radio compass",Serial ferentiated currents may be applied to any amamfeanaaciso l n l l2,188,611.

UNITED s-TATEs PATENT oF/FlcEw mulaslsm'l'o "Lowell E. Norton,Collingswood, N. J., assigner to A Radio Corporation of America, acorporation of Delaware Application June 1s, 193s, serial 10.214,473

1 claims. conso-ss) This invention relates to impulse generators is thelimiting valueof the ratio of the increment and more specifically toimpulse generators in? of the function to the increment of the variable,which sinusoidal currents are applied to the inas the latter incrementapproaches zero. Briefly Y put of the generator and sharply definedimthe circuit derives the differential of the applied 5 pulses, having axed phase with respect'to the current, or the voltage derived dependsupon 5 sinusoidal currents, are obtained in the generthe rate of changeof the applied current. The ator output. l y negative portions I9 ofthedifferentiated cur- One of the applications of this invention is rentsare of larger amplitude and more sharpdescribed in the copendingapplication entitled ly defined than the positive portions. The dif- No.216,825, filed June 30, 1938, by David G. C. plifer 2| for furtheramplification, and there- Luck, and assigned to the same assignee as the,after applied to a second differentiation circuit instant application.In the above-mentioned co- 23. The amplifier, if it is a single stage,will pending application, currents of sine wave form reverse the phaseof the applied currents. The

l5 arederivedfromarotating radio field. The phase last mentioneddifferentiated currents 25 have 15 of the field is determined byconverting the depositive peaks which are quite sharply dened. rivedsine Wave currents into sharply defined im- The impulse output4 stage 21is so negatively pulses, which have a fixed phasal relation to thebiased that only the upper portions of the posisine waves, andindicating the phase of the im'- tive peaks 25 are effective. The smallnegative pulses with respect to a reference phase. swings may beneglected because Ca discharges 20 One object of this inventionl is theprovision through resistance 41 only on positive grid 'swings of meansin which sharply defined impulses are to tube 45. The output currents 29are very generated from sine wave currents. Another obsharply definednegative impulses which have ject is to provide means for generatingsharply the same phasal relation as the sine wave input defined impulseshaving fixed phasal relations currents. Output currents 29 could also be25 with respect to the sine waves from which the sharply definedpositive impulses by placing disimpulses are generated. A further objectis to charge resistance 41 in cathode circuit. provide means wherebysine wave currents may One practical embodiment of the invention is berectified, the rectified currents made asymillustrated in Fig. 2. Theinput circuit 3I is 30 metrical, the asymmetrical currents once orconnected to a thermionic' amplifier 33. The 30 twice differentiated,and the differentiated curoutput of the amplifier 33 includes a tunedcirrents applied to a gaseous discharge tube from cuit 35` which isresonant to signal currents of which impulse currents are derived. thedesired frequency. The resonant circuit 35 In describing the invention',reference will be is coupled to a second resonant circuit 31. The madet0 the accompanying drawing inv.which; pair 0f Circuits .and a SeriesCircuit 39 OIm a. 35

Figure 1 is a block diagram illustrating the filter which attenuatescurrents of undesired fre-` invention; and quencies. The filter isconnected to the diode Figure 2 is a schematic circuit'diagram of onesection of a thermionic tube 4I. The diode is embodimentof theinvention. connected to a discharge circuit including a re- 40 Referringto Fig. l, currents of sine wave form sistor R and a capacitor C. TheValues of the 40 I, which mayinclude undesired frequencies, areconstants C and R and the-diode rectifier imapplied to the input of anamplifier 3. The ampedance are so related that they rectified curpliiiedcurrents 5 are applied to a filter 1, which rents have an asymmetricalform. passes currents of the sine wave 9 desired. The The dischargecircuit CR is connected to the sine Wave currents are applied to arectifier II, amplifier input section of the thermionic tube 4 5 whichpreferably is of the half wave type al- 4I. The input section of theamplifier tube 4I though full wave rectification may be used. Theincludes a differentiating circuit which consists rectified currents I3are applied tola discharge of a. capacitor C1 and a resistor R1. Theoutcircuit having a time constant, which makes the put circuit includesa second differentiating Wave form of the currents I5 asymmetrical.'I'he circuit CzRz. ,One terminal of the resistor Rz 50 currents ofasymmetrical wave form are applied is connected to a source of negativebias voltage to a differentiation circuit I1. The term dif- 43. Thepositive terminal of the source 43 is ferentiation is used in themathematical sense; connected to the cathode of a gaseous discharge i.e., the process of finding the derivative of a. tube'45. The junction ofthe capacitor C2 and given function. The derivation of a function -theresistor Rz is connected to the grid of the 55 gaseous discharge tubeI5. The output oi the tube 45 includes a potentiometer 41 across whichthe output impulses are obtained.

Thus an impulse generator has been described in which sine wave currentsare amplified, illtered and applied to a rectifier. The asymmetricalcurrents from the rectifier discharge circuit are differentiated,amplified and, if desired, again differentiated. These differentiatedcurrents trigger a gaseous discharge tube. The output circuit of thedischarge tube includes sharply delned impulse currents of the samephasal relation as the sine Wave currents. If the input currents are ofsufiicient amplitude and of sufficiently pure sine wave form, theinitial steps of amplifying and filtering may be omitted. Likewise, insome applications one differentiation may be used in place of two.

I claim as my invention:

1. The method of generating sharply defined impulses by means of agaseous dischargey device which includes rectifying sine wave currents,altering the wave form of the rectified currents to produce anasymmetrical wave form, differentiating said currents of asymmetricalwave form, applying said differentiated currents to said gaseousdischarge device to establish therein gaseous discharge currents, andderiving therefrom sharply defined impulses:

2. The method of generating sharply dened impulses by means of a gaseousdischarge device which includes rectifying sine Wave currents, a1-tering the wave form of the rectified currents to produce anasymmetrical wave form, differentiating said currents of asymmetricalwave form, amplifying said differentiating currents, applying saiddifferentiated currents to said gaseous discharge currents device toestablish gaseous discharge currents, and deriving therefrom sharplydefined impulses.

3. 'I'he method of generating sharply dened impulses which includesrectifying sine wave currents, altering the wave form of the rectifiedcurrents to produce an asymmetrical wave form, differentiating saidcurrents `of asymmetrical wave form, amplifying said differentiatingcurrents', further differentiating said amplified currents, establishinga gaseous discharge current as a function of said amplifieddifferentiated currents, and deriving therefrom sharply definedimpulses.

4. The method of generating sharply defined impulses which includeamplifying sinusoidal currents, filtering said amplified currents,rectifying said amplified currents, altering the f'orm of the rectifiedcurrents, differentiating said last mentioned currents, amplifying saiddifferentiated currents, further differentiating said amplifleddifferentiated currents, establishing gaseous discharge currents asfunctions of said last mentioned differentiated currents, and derivingfrom said discharge currents sharply defined impulse currents.

5. An impulse generator including, in combination, a source of sine wavecurrents, means for rectifying said currents, means including adischarge circuit for making the wave form of the rectified currentsasymmetrical, means including a circuit for differentiating saidcurrents of asymmetrical wave form, 'a gaseous discharge tube, means forapplying said differentiated currents to said tube, and means includingconnections in the output circuit of said tube for deriving therefromsharply defined impulses.

6. An impulse generator including, in combination, a source of sine wavecurrents, means for rectifying said currents, means including 4adischarge circuit for making the wave form of the rectified currentsasymmetrical, means including a circuit for differentiating saidcurrents of LOWELL E. NORTON.

